US1696380A - Instrument control - Google Patents

Description

[NYE/(TOR W////am 4/: Arron/Ins W. M. BROWER INSTRUMENT CONTROL Dec. 25 1928.

Filed March 29, 1926 Y t is a further object of this invention to Patented Dec. 25, 1928.;

UNITED STATES v P TENT WILLIAM M. imowim, or Pam Limo, olamroimra, ASSIGNIOBI To FEDERAL". GRAPH comraNY, or SAN FRANCISCO, camroanra, A-coa'rom'nonor cam- FORNIA.

mmame msba I Application flledliarch 2a, 192s-. sena1 no. saeosff This invention relates generally to devices for controlling electrical instruments and'has instrument which will permit accurate and smooth control of the instrument.

' construct avcontrol for a tuning instrument which will. permit the positioning of the control shaft in alinement with the periphery of an indicating drum or dial provided upon the shaftof the instrument.

'-' It is a furtherobject of this invention to secure a novel arrangement for controlling the shaftof a tuning instrument adapted to be 2O mounted behind an instrument paneL- It is proposed to provide an indicating dial on the instrument shaft, the periphery of which is visible through an aperture in the panel and e to operatively connect the instrument shaft to a control shaft arranged in vertical1aline ment with the indicatingdial.

It is a further object of this invention to provide a combination indicating dial and pull'ey wheel on the shaft of .an electrical tuning instrument, the pulley serving as a means for controlling the instrument.

Further objects of the invention will appear from the following description in which the preferred embodiment of the invention has been set forth. various modifications may be inadewithin the scope of the appended claims.

Referring to the drawings; a Figure 1 is a side view showingthe invention as applie'dto a tuning instrument mounted behind an instrument panel. 1

Fig, 2 is a plan view-of the invention as shown in Fig. 1, the instrument panel being shown in cross section.

Fig. 3 is a detail view showing the resilient means for .tensioning and tracking the driving belt.

In radio apparatus it is necessary tomake very close adjustments of the various tuning instruments such as variometers or variable condensers. Manual control means must be provided which will permit very small angular movement of the control shaft and this control should be smooth at all times; that is,

It is to be understood'that itshould not have any back-lashor lost motion. In the past it has been proposed to em-' ploy gear trains or friction wheels but these cessful in securing thedesiredsmoothness of operation and'have also been expensive to mechanisms .have not-proved altogether suemanufacture! "Myinvention solves this prob lem by employing aisimple form of belt drive which in addition to securing smoothness of 1 r variable condenser having the usual stator plates 11 and rotor plates 12, the rotor plates being mounted upon a rotatable shaft 13.

an electrical tuning instrument 10 such as a and 15 serve. to retain the rotor and stator plates in assembled relation.. The variable condenser is adapted to be mounted behind an lnstrument panel 17 preferably with its shaft 13 in horizontal position. Thus the condenser has been shown as secured to a metal sheet 18' panel 17. .Secured adjacent one end of the shaft 13 there is an indicating drum or .dial 20 having a peripheral portion 21 which is provided with suitable graduations. The peripheral portion 21 is preferably of sufficient diameter to extend through an aperture 22 provided in the panel 17 so as to be viewed from the front of the panel. A stationary indicia 23 may be provided on the panel for cooperating with the dial 'so that an operator may set the instrument to any desired position.

To control the movement of the shaft 13 there is provided a pulley wheel 25 which is preferably secured to the dial 20. In the construction shown a combination dial and pulley wheel is employed which is constructed of a single integralpiece of suitable material, such as fibre or a phenolic con-'- portion 21. Thus the controlshaft nayl-be 75 Suitable means such as a pair of end plates 14 i -ment of the control shaft.

said to be in vertical alinement with the periphery of the.dial. For retammgshaft 2G in operative position a bracket 27 is mounted -on the end plate 14, this bracket carrying the pulleys 25 and 31 there is a flexible belt or cord 36 which also passes over the idler pulley 35, this latter pulley being positioned in the manner shown in Fig. 3 so as to track the belt 36 upon the two pulleys; The resilient arm 34 serves to press the idlerpulley in a direction to tension the belt 136.

In operation comparatively large angular movement of the control knob 30 will effect small angular movement of the instrument shaft 13. because of the difference in size between the pulley wheels 25 and 31. Furthermore, because of the use of a flexible tensioned drive the control is perfectly smooth and free from all uneven and jerky movements. Upon reversal of the direction of movement there will be no back-lash or lost motion. The positioning of the shaft invertieal alinement with the indicating dial, whichis made possible through the use of this particular driving connection, materially facilitates manipulation of the device by an operator.

As the entire control is secured to the variable condenser it may be conveniently removed or attached to the panel as a unit merely byremoving the knob 30 so as to permit the control shaft 26 being removed or inserted through the panel.

This case is a continuation in part of my application Serial Number 753,653, filed December 3, 1924.

I claim:

1. In a visual indicator of the class described the combination with a panel formed with an opening therein, a rotatable shaft, an

indicator drum secured to said shaft and having graduations thereon vlsible through the opening in said panel, a rotatable control shaft in alignment with said indicator drum, and flexible means for operat-ively connecting said shafts, said means extending in planes substantially-at right angles to each other.

2. Ina visual indicator of the class described an electrical tuning devicehaving a rotatable shaft, an instrument panel having .an aperture therein, means for operatively mounting said device adjacent saidinstrument panel with the shaft in spaced parallel relationship behind said panel, an indicting drum secured to said shaft and having a portion of its periphery visible through the aperture in said panel, a control shaft projecting through said panel and normal to the same, said control shaft lying in a plane normal to said first shaft and central of said drum, and

.nleans operatively connecting said shafts for driving said drum in accordance with movement imparted to said control shaft from the front of said panel.

In a visual indicator of the class described an electrical tuning device having a rotatable shaft, an indicator drum secured to said shaft, a pulley wheel secured to the shaft adjacent the indicator drum, a rotatable control shaft disposed normal to said first named shaft and aligned with said drum, a. pulley on said last named shaft, and a belt operatively connecting said pulleys, said belt being twisted from the plane of said indicator drum to the plane of the pulley on said last named shaft whereby mot-ion imparted to said control shaft causes corresponding movement of said drum.

4. In a visual indicator of the class de scribed an electrical tuning device having a rotatable shaft, an instrument panel having an aperture therein, means for operatively mounting said device adjacent an instrument panel, an indicating drum secured to said shaft and having a portion of its periphery visible through the aperture in said panel, a control shaft projecting through said panel in vertical alignment with said aperture, and a flexible belt operatively connecting said control shaft and said first named shaft, said belt being twisted from a plane parallel to a central plane through said indicating drum to a plane normal to the axis of said control shaft.

5. In a Visual indicator of the class described an electrical instrument having a shaft rotatable to vary the electrical properties of the same, means for mounting said in strument behind an instrument panel with said shaft in'horizontal position, an indicating drum secured to said shaft and having a portion of its periphery projecting through an aperture in said panel, a control shaft nor mid to said first named shaft and in vertical. alignment with the center of the periphery of said drum, and means operatively connecting said shafts whereby said instrument shaft may be controlled by rotation of the control shaft from a position adjacent the projecting portion of said indicating dru'm.

6. In a visual indicator of the class desmall pulley wheel, and a flexible belt operatively connecting said shafts whereby motion imparted to said control shaft causes corresponding movement to said rotatable drum.

7. In a visual indicator of the class described an electrical tuning instrument mounted behind an instrument panel and having a rotatable'shaft for varying the same, a rotatable drum having peripheral graduations secured to said shaft andvisible through an aperture formed in said anel, a

pulley formed on one face of said rum, a control shaft normal to said instrument shaft and in alignment with the center of said drum, said latter shaft having a; relatively small pulley wheel, a flexible belt operatively connecting said pulleys and spring means for tensioning and tracking said belt upon said pulleys, said control shaft being operable from the front of said panel.

8. In'a visible indicator of the class described an electrical instrument having a rotatable shaft for varying the same, a rota-table control shaft mounted upon said electri,-'

cal instrument and disposed normal to said instrument shaft, a pulley wheel on said control shaft, a dial havin a circumferential graduated portion, said ial being secured to said shaft with the circumferential portion scribed an, electrical instrument having a ro-' tatable shaft for varying the same, a rotatable control shaft mounted upon said electrical instrument and disposed normal to said instrument shaft, a combination indicating dial and pulley wheel secured to said shaft, said dial having a peripheral graduated portion of greater diameter than the pulley wheel portion and being disposed in a plane normal to the instrument shaft and including the control shaft, a pulley on the control shaft,

and a flexible belt operatively 'connectin the pulley wheel on the control shaft an the pulley wheel portion of saiddial, said belt changing'its direction in the course'of its travel from one pulley wheel to theother,

In testimony whereof, I have hereunto" set my hand.

WILLIAM M. BRowER.

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